Skimmer

A skimmer (from a Northern English dialect word meaning 'to brighten' or 'to sparkle', perhaps related to our word 'shimmer'), is a sprinkling of words or charms intended to reinforce the effect of a spell. For example, when Gilbert Norrell constructs a spell to summon John Uskglass, he adds a skimmer of supplication, meant to induce the King to look favourably on those summoning him[66].